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  • Writer's pictureAllison Koch, MS, RD, CSSD, LDN

Nutrition For New Or Beginning Runners: 3 Common Mistakes And How To Fix Them

Updated: Sep 21, 2022

As a sports dietitian who works with endurance athletes, and a runner myself, I receive a lot of questions about what to eat and drink to adequately support training and fuel performance. I also observe many of the same mistakes time after time in my practice.

Here are the 3 most common and my tips on how to fix them.

1) Not fueling enough before your workouts or long runs

Did you know that you burn roughly 100 calories for every mile you run? It is important that you take in enough calories beforehand to ensure you can stay fueled throughout the entirety of the run. For example, if you only take in about 200 calories prior to a 10-mile run (or nothing at all if you wake up and roll out the door on empty), after you burn through those 200 calories, your body will begin to utilize whatever you have stored from the day/night before. Then it will tap into your reserves – like your muscle mass – which is the last thing you want.

To prevent under-fueling before your long runs or weekday workouts, here’s what I recommend:

  • At least 1-4 hours before your long run or workout have a meal consisting primarily of carbohydrates and a little bit of protein/fat to help sustain you and stabilize your blood sugar. I recommend aiming for at least 400-600 calories (the longer the run, the more you should try to take in).

  • Example pre-long run meals: a bagel with peanut butter and a banana; oatmeal with chia seeds, blueberries and a drizzle of honey; yogurt, granola and an orange; or even a turkey sandwich and handful or pretzels. Limit excess fat, fiber or caffeine to decrease the chances you’ll end up needing a pit stop.

2) Skimping on fuel during the long run

As you begin to take on longer distances, you will inevitably burn through your pre-workout fuel and need to take in some nutrition during your long runs. Adequately fueling yourself during your run will help you perform and feel better not only during your run but after as well. Speaking from experience – the best I’ve ever felt post-marathon was very much in part to taking in the most nutrition I possibly could during the race.

So how much and how often? Everyone is different with what they need and can tolerate; figuring out what works for you now will help you be prepared for race day!

Some general rules of thumb:

  • You need at least 30 grams of carbohydrate/hour of exercise to maintain blood glucose levels. The more you can take in the better you will feel and likely perform (most elites take in closer to 60 grams/hour). To put it in simpler terms - that’s at least 100 calories per hour. You’ll want to fuel early and often.

  • Don’t wait until you run out of gas. Start taking solid nutrition at about the 45-60 min mark of your long run and continue every 45-60 minutes. This could be a combination of solid nutrition like a gel, gu, a serving of Bloks/gummies or sport beans, a bar—whatever works for you (I’ve even had athletes consume potatoes, raisins or applesauce mid-run), plus sips of a sports drink.

  • Avoid taking solid nutrition and sports drinks together. The electrolytes from both may overwhelm your digestive system and result in stomach upset. Only take your solid nutrition with water and then alternate between it and your sports drink.

3) Underestimating the importance of post-workout nutrition for proper recovery

Proper nutrition is also essential to help you recover from all the hard work you just put into your long run or workout. This includes appropriate amounts of carbohydrate to Refuel glycogen (the storage form of carbohydrate in our muscles and the main energy source during exercise), fluids to Rehydrate, and protein to Repair the damage done to our muscle tissue; otherwise known as the 3 Rs of post-workout recovery nutrition.

The sooner you eat and drink something, the better you’ll feel. In addition, you’ll help boost your immune system. Whenever we do high intensity, long duration bouts of exercise we suppress our immune system, leaving us at risk for illness. The sooner you can get some high-quality fuel into your body the less likely you’ll be to get sick.

I recommend at least 35-50 grams of carbohydrate and 10-20 grams of protein within the first 2 hours (roughly 200-300 calories). Ideally, you’ll have a balanced meal. But if you can’t get a meal in, a snack such as the following will suffice until you can:

What you do before, during and after your workouts and long runs can make or break your run. You want to get the most out of the time on your feet – so make sure your fueling strategy supports that. Don’t forget – practice makes PRs. If you start practicing your race day nutrition plan now, come race day there will be no questions about what you need to do from a fueling standpoint to achieve your goals. Happy training!


Have questions/unsure what you should be eating/drinking to optimize your performance? Reach out to Allison today to set up a free discovery session and/or learn about the 1-on-1 services she offers!

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